Space Circles Are Proof of a Pre-Big Bang Universe?

Ring-like patterns in the sky could be ghostly imprints of a universe that existedbeforethebig bang, according to a controversial new study.

If the theory is correct, the cosmic rings may be the first real-world evidence that our current universe is just the latest in an endless string of recycled universes, the study authors say. (Related:"Universe Reborn Endlessly in New Model of the Cosmos.")

Astronomers found the circular patterns in a new analysis of thecosmic microwave background(CMB), which is the radiation left over from the big bang that now permeates the universe.

Within the newly described rings, many of which are nested like ripples in a pond, the temperature is more uniform than elsewhere in the CMB sky. (Seepictures of other odd rings and spirals in space.)

One possible explanation for these rings is that they were created whenblack holescollided in a previous universe, according to Roger Penrose of theUniversity of Oxfordin the U.K. and Vahe Gurzadyan of theYerevan Physics Institutein Armenia.

Scientists think that when two black holes crash together, they emit ripples of energy known as gravitational waves. The more massive the colliding black holes, the more numerous and powerful the waves.

Gravitational waves distort the fabric of space-time and—according to Penrose and Gurzadyan—the waves can leave imprints of their passage in the form of ring-like patterns.

If our universe is one in a series of reborn universes, this would mean that the rings survived our big bang and now"allow us to 'see through' the big bang into the previous aeon,"Penrose and Gurzadyan write in their study. Neither study author could be reached for comment.

(Get theten biggest cosmic mindblowers of 2010as chosen by National Geographic News editors.)

If the concept of patterns surviving a big bang event sounds far-fetched, don't worry: Even other astrophysicists find it hard to believe.

"That part confuses me as well,"said James Zibin, of Canada'sUniversity of British Columbia."It just seems odd to me that the effects of these ripples could survive at all during these transitions. ... That's one of the many details that hasn't been fleshed out."

Universe Gets Recycled?

The new paper,published earlier this month on the Cornell University website arXiv.org, is the latest piece in a model of a cyclical universe that Penrose has developed over several years.

According to his theory, the big bang that created our universe is not unique. At least one earlier big bang occurred, giving rise to a universe that existed before ours. Countless more universes could have existed before that one, he thinks.

(Related:"Big Bang Poured Out 'Liquid' Universe, Atom Smasher Hints.")

Penrose calls each cycle of the universe an aeon, and each aeon lasts for an unimaginably long time—much longer than the age of the current universe, which is already 13.7 billion years old.

An aeon starts with a big bang, and over time the newborn universe evolves from a sea of dilute and homogenous particles into ever more complex structures such as galaxies, stars, planets, and life.

All the while, the universe is expanding at an accelerated rate, presumably stretched apart by the same mysterious dark energy that is driving the expansion of space-time in our current universe. (Related:"New Proof Unknown 'Structures' Tug at Our Universe.")

Inevitably, however, all the matter in the universe is ingested by the supermassive black holes that lurk in the hearts of large galaxies, such as the one in our own Milky Way, according to Penrose's theory.

(Also see"Every Black Hole Contains Another Universe?")

These black holes grow as they feed, colliding and combining into even larger black holes. The gravitational waves created by these black hole collisions are what drive the CMB rings, the theory goes.

Eventually the monster black holes consume matter until nothing is left. Physicist Stephen Hawking proposed in the 1970s that, when black holes stop taking in matter, they lose mass via radiation, with smaller black holes losing mass faster than larger ones.

Based on that theory, over billions more years the remaining black holes would"evaporate,"converting their ingested matter into radiation. At this point in the aeon, the universe—now old and large beyond imagining—is once again a sea of uniform particles.

Penrose theorizes that the universe then undergoes a transformation that essentially compacts it back into an infinitesimally small point, setting the stage for the next big bang.

According to this theory,"everything that is big becomes small, and everything cold becomes hot, so that the {ancient} universe, which is big and cold, becomes dense and hot,"said astrophysicistAmir Hajianof the Canadian Institute for Theoretical Astrophysics (CITA) in Toronto.

Penrose and Gurzadyan don't explain what drives this transformation, though. As with other aspects of the model, this part needs more explanation, said Hajian, who is aco-author of one of three independent papers, all recently posted on arXiv.org, that challenge the new study's claims.

"In principle, it works on paper, but it's still missing details and quantitative predictions,"Hajian said.

Space Circles Are"Perfectly Normal"

None of the challengers doubt the existence of the CMB rings:"We confirmed that they were there,"said the University of British Columbia's Zibin, who is aco-author of another one of the rebuttal papers.

"We could see exactly the signals that they described. So that part isn't in question. ... Where we differ is in our interpretation of the significance the signals."

Instead, all three papers note that Penrose's cyclic model doesn't include a process called inflation.

The inflationary theory says that the early universe went through a period of hyperexpansion that helped it reach its current size and shape. Inflation helps solve a number of problems with the big bang theory,some of which were revealed by studies of the CMB.

For example, one potentially puzzling aspect of our universe is that it appears to be homogeneous—that is, when viewed on the large scale of galaxy clusters, different parts of the universe look essentially the same.

Inflation explains the universe's uniformity, because any clumping of matter in the early universe was smoothed out by hyperexpansion.

However, according to Penrose, if an earlier universe existed before our own, and that universe expanded at an accelerated rate the same way ours is doing now, inflation is not needed.

The idea is that"the accelerated expansion in the previous aeon smoothed the universe out, and that takes the place of inflation in the standard picture,"Zibin said.

(Also see"Time Will End in Five Billion Years, Physicists Predict.")

Each of the rebuttal papers describes the results of computer models that simulate hundreds of CMB skies resembling the actual radiation pattern found in our universe. Each simulation used inflationary theory as its foundation.

If the ripples in the CMB are evidence of the cyclic model of the universe, then the ripples should not be present in the simulated CMB skies because, according to Penrose, they should not appear in an inflationary universe.

But the rings do show up in the simulations.

"We looked for these patterns, and we could see exactly the same kinds of patterns. We could see similar numbers of them, with similar shapes and sizes,"Zibin said."If {Penrose} wants to argue that this cyclic model is the correct one, he has to find some signature that would distinguish between his model and inflation. These rings are not that signature."

CITA's Hajian agreed:"The circles are not anomalous in any way. They are perfectly normal, and {our models} show that they can happen in a universe that is consistent with inflationary theory."

Instead of evidence for previous universes, the rings could be a kind of optical illusion created by natural variations in the CMB, Zibin added.

"If you look hard enough, you can find all sorts of things"in the CMB, he said."That's one of the lessons of this, I think."

forNational Geographic News

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National Snow and Ice Data Center Gets a Cool Makeover

This story is part of aspecial seriesthat explores energy issues. For more, visitThe Great Energy Challenge.

An energy irony clouds the work of the powerful U.S. computers that have tracked the retreating Arctic sea ice. While the data servers handle the information behind the ever-worsening satellite images of global warming's impact, they are burning a lot of coal.

In fact, theNational Snow and Ice Data Center(NSIDC), funded largely through grants from U.S. government agencies but located at theUniversity of Colorado at Boulder, needs 100 kilowatthours per hour of fossil fuel power to process data on the state of the world's frozen regions. That's roughly the amount of electricity it takes to power about 80 average U.S. homes, according tothe latest figures. And about half of that power is spent not to crunch data, but just to cool the equipment.

"Here we are working on climate research, and our data center is consuming an awful lot of power,"said David Gallaher, NSIDC's technical services manager."Even in the dead of winter, these things are cranking full-tilt, trying to chill off the 100°F-plus (37°C) heat coming off the back of these units."

With the cool air of the Rocky Mountains all around, it didn't make sense."We said, 'Why are we doing this?'"Gallaher said."Why don't we dump the warm air outside and pull in the cool air?"

Now, a $600,000 renovation, largely funded bya National Science Foundation (NSF) grant, seeks to do just that. Along with better equipment and an innovative evaporative cooling technology, it aims to make the NSIDC computing center one of the most energy-efficient data centers in the United States.

A Growing Mission

NSIDC's job has grown exponentially since it was established in 1982 as part of the University of Colorado's Cooperative Institute for Research in Environmental Sciences. The center started out as an analog archive and information center, but now manages remote sensing data fromNASA's Earth Observing Systemsatellite program. NSIDC currently archives and serves more than 91 terabytes of Earth science data to researchers around the world.

NSIDC is entirely funded by competitive grants, with the largest share of funding from NASA, and smaller shares from NSF and the U.S. Department of Commerce'sNational Oceanic and Atmospheric Administration. Among the recent work of the scientists there:examining the causes for the loss of sea icein West Antarctica, and producing the maps that showed that Arctic sea ice extent this past September wasthe third-lowest in the satellite record(just behind record-setting 2007 and the second-lowest year, 2008.)

(Related:Decline of Arctic Ice Continued in 2008)

But those calculations would be impossible without powerful computers and servers to manage the data.

With 70 servers in two rooms, NSIDC's facility was a fraction of the size of the largest data centers in the world, like Switch Communications' hugeSuperNAPin Las Vegas, with racks for 7,000 servers. Still, by using more energy-efficient technology, NSIDC found it could do a lot better.

Switching to higher-density memory disks that use about the same amount of energy as the old disks, but store more data, NSIDC was able to consolidate its data center from two rooms to just one. The number of servers also was cut by 60 percent through"virtualization."That means replacing several dedicated servers operating at a low average processor utilization level with a single"host"server that operates at a higher average utilization level.

"A typical server uses about 5 percent of the CPU {central processing unit} that's sitting there,"Gallaher explains."But it's hard to put a whole lot of different processes on it. Certain applications don't play well with others. Virtualization allows us to put many servers on that one physical server, and yet each {virtual} server is custom-built to its own needs. Each application gets exactly what it needs."

(Related:Pictures: Seven Supergreen U.S. Government Buildings)

The new data center, to be completed next summer, also is being rearranged so the rows of server racks will no longer face the same direction. Instead, the direction in which the rows face will alternate, so the backs of the servers don't spill heat onto the front of the servers on the adjoining aisle. The aisles will be sealed with plastic sheets so that the cooling systems don't work overtime cooling the hot air.

Using the Cool Air

The project includes a 25-kilowatt rooftop solar array to replace some of that coal power. But perhaps the greatest innovation is how the center will cut down its need for traditional air-conditioning simply by taking advantage of the surrounding geography."ThisisBoulder,"says Gallaher. Filtered outdoor air is expected to provide most of its cooling needs for the equipment. And on hot days when that's impossible, the data center is installing a new system that uses indirect evaporative cooling—a technology that uses no compressors, but blows air through water, and takes advantage of the change in temperature when the water evaporates.

"Ninety percent of the time, the total power used by this whole cooling system will be about equal to the power your car air conditioner uses,"Gallaher says."We're quite ecstatic about it."

The 90 percent reduction in cooling costs is expected to pay for the cost of the system in about three years. The energy savings add up to a 45 percent reduction in operation costs for NSIDC each year.

Although NSIDC was located in the advantageous climate long before the growth of its data center, some energy efficiency experts believe that geography soon will be more of a consideration when server facilities are sited.

"People put data centers in the Pacific Northwest because there is fairly cheap hydropower there,"says Otto Van Geet, aNational Renewable Energy Laboratoryengineer."You could put data centers in the middle of Texas where the wind resource is good, or in the Midwest, etcetera. I think that is something you'll start to see more of—people taking {energy sources} into account when they choose where to put data centers."

(Related:The Big Thaw)

Candace Adorka is a reporter with Medill News Service in Washington, D.C.

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Can Geothermal Energy Pick Up Real Steam?

This story is part of aspecial seriesthat explores energy issues. For more, visitThe Great Energy Challenge.

Steam rising from a valley just north of San Francisco reminded early explorers of the gates of hell. Others saw the potential healing powers of the naturally heated water, and still others realized the steam could drive turbines to generate electricity.

It's been 50 years since power plants began running off the pools of steam that sit under California's Mayacamas Mountains. The pioneering plants in the area known asThe Geysershighlighted the promise of geothermal energy, internal heat from the Earth with vastly greater energy potential than that of fossil fuels. But geothermal, virtually free of carbon emissions and more reliable than intermittent wind and solar energy, still provides only a small slice of the world's energy.

Now amid the rush to alternative energies, geothermal advocates sense a new chance to mine the heat rising from Earth's white-hot core. They plan to generate man-made steam by pumping water deep underground into hot, dry rocks in what's called enhanced or engineered geothermal systems. They also despair that governments and businesses aren't investing enough in the sophisticated technology needed to unlock the deep-seated energy.

"There's a window of opportunity where geothermal can play a part in our energy future, and we risk missing it,"says David Blackwell, a geophysicist at Southern Methodist University.

(Related:Biothermal Energy Basics)

Blackwell contributed toa broad study released in 2007that predicted geothermal could provide one tenth of U.S. power by 2050. But that progress depends on new technology that can move geothermal beyond naturally occurring steam deposits. These enhanced geothermal systemswoulduse tricks learned from oil and gas drilling. They would fracture rock with high-powered streams of water, generating steam to power turbines running above ground.

"That's really the holy grail of geothermal: that you can go anywhere and extract the Earth's heat,"Blackwell says.

Limited Availability

It also remains experimental. For now, geothermal energy depends on hot water and steam deposits lying within two miles or so of the Earth's surface."You still have to be in the right area to exploit geothermal,"says Max Krangle, managing director ofABS Energy Researchin London, England. That means population or industrial centers must be near steam reservoirs to benefit from them, a scenario that could limit geothermal's contribution to the world's energy needs, Krangle says.

Some countries astride strong volcanic activity have eagerly exploited their geothermal resources, which generates about 18 percent of the electricity in the Philippines, about 25 percent in Iceland, and 26 percent in El Salvador,according to the Geothermal Energy Association.

(Related:How Iceland Uses Geothermal Energy)

Still, ABS analysts predict that power generated from geothermal deposits will grow slowly through 2020. It will lag behind the gains of other energy sources and still make up just a small slice of the electric pie—about 0.2 percent of world production. Fossil fuels would fall a bit from about 67 percent of generating capacity to 61 percent, with gains in wind and solar making up most of the difference, ABS estimates.

Groups promoting geothermal, such as theGeothermal Resources Council, think the technology could grow more rapidly. They cite a coming spurt of new geothermal projects, with wells planned to exploit natural steam deposits in North America, Africa, and Indonesia, among other places. Kenya, for one, has committed itself to aggressive drilling in its stretch of the East African Rift Valley, a geologically active area thought to hold large geothermal reserves.

Kenya made its move after a recent drought that tested its dependence on hydropower, including a shutdown of its main hydro dam. By 2030, Kenya aims to have generating capacity of 5,000 megawatts of geothermal electricity, or more than twice the capacity of all of Kenya's current electrical plants. It's also almost twice the 2,800 megawatts of geothermal generation capacity that ABS says now exists in the United States, the current world leader. (Worldwide, geothermal produces about 10,000 megawatts of capacity that can meet the needs of about 60 million people, according to theGeothermal Energy Association).

Before exploring new drilling sites, Kenya is first expanding several geothermal plants it operates in the Rift Valley. The power stations sit inside the country's Hell's Gate National Park, also named for the natural steam releases seen by early European explorers in the 1800s.

Expanding Into New Territory

Utilities have commissioned a number of projects to expand plants above natural deposits in North America. They include plans at California's own hell's gate, later named The Geysers—a misnomer, as there are no geysers there—already the site of the world's largest geothermal plant.

But it's the man-made steam that would thrust geothermal into prominence, according tothe 2007 study, which was funded by the U.S. Energy Department and led by the Massachusetts Institute of Technology. Several dry-rock projects are under way, including a system planned for Oregon byAltaRock, one of several companies with projects in the works to create underground steam. AltaRock's backers include the Energy Department and high-profile investors such as Google, which has been plowing money into alternative energy projects.

Enhanced geothermal applies rock-cracking technology that's already widely used in oil and gas drilling. One challenge is making it work amid the underground heat needed to generate steam, says Susan Petty, who helped found AltaRock after contributing to the 2007 report.

"We have technology that can do it today—this is not the Easter Bunny,"she says. But the new approaches are expensive, making it difficult to compete financially with conventional electrical plants, notably those that burn coal or gas.

While cleaner than fossil fuels, man-made steam faces its own environmental concerns, primarily the threat of small, man-made earthquakes. In 2006, a quake shook Basel, Switzerland (map), amid drilling and underground rock-cracking for an enhanced geothermal system there. The quake forced that project to shut down, and its sponsor had to make millions of dollars in payments for damaged buildings.

Blackwell at SMU jokes that the damage likely included"a lot of cracks that were hundreds of years old."He says the threat of dangerous quakes is a"red herring"that has slowed investment, particularly federal money.

Petty at AltaRock says small quakes always accompany the rock fracturing in oil-and-gas drilling, but industry has learned how to monitor and control their severity. The Basel project targeted a particularly sensitive seismic area, and drilled in the middle of a city because of plans to divert steam for heating buildings, another use of geothermal energy.

"There were people who felt the Basel plan was high-risk,"she says.

AltaRock suffered its own setback when it failed in an effort to redrill an existing well at The Geysers, where electricity production has fallen as steam has been depleted. But Petty says she continues to believe in enhanced geothermal systems, encouraged by recent tests of some of AltaRock's technology."I have a lot of confidence we're going to be able to do this."

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Bee Viruses Spread via Flower Pollen, Study Says

Viruses that could play a role in the recent decline inhoneybeecolonies may be spreading through flower pollen, new research finds.

What's more, a number of wild pollinators, such as bumblebees, yellowjackets, and wasps, can also become infected with viruses in the pollen.

In hives affected by colony collapse disorder—a phenomenon that surfaced in U.S. honeybee colonies in 2006—worker bees vanish en masse. Some studies have suggested that Israeli acute paralysis virus (IAPV), first identified in 2002,may be contributing to the bees' demise.

Scientists knew that several viruses that infect honeybee colonies are transmitted from one bee to another within the hive through the bugs' saliva or from an infected queen to her eggs.

But how the viruses moved from hive to hive was relatively unknown, said study leaderDiana Cox-Foster, an entomologist at Pennsylvania State University.

"People suspected the viruses were being transmitted by bees visiting other colonies, but no one really knew there was evidence for the virus moving into other {insect} species,"she said.

Contaminated Pollen Infecting Bees

Bees collect nectar to make into honey and to make"bee bread"—pollen packed by workers into tiny balls with a bit of nectar added.

(See relatedpictures:"Rare Bees Make Flower-Mud 'Sandwiches.'")

When Cox-Foster's team collected university-owned honeybees as the insects were harvesting pollen, they found that some bees were healthy but their pollen loads were contaminated. This indicated that at least one type of virus—deformed wing virus, another fatal bee disease—was spreading from the pollen to the bees, and not always the other way around.

In a separate experiment, the team collected and examined wild bumblebees and wasps and discovered molecular evidence of viruses that can infect honeybees.

When bees from a healthy hive visited the same flowers previously visited by sick bumblebees, the colony contracted the virus within a week, the team found.

Cox-Foster noted that bee viruses in general don't have to be lethal:"It's sort of like the common cold. If you're healthy, you may not catch the cold your neighbors have. We need to ask why the bees are more susceptible to these viruses."

For instance, other stressors, such as pesticides and a lack of good nutrition, may be behind the bees' lack of resistance, she said.

Other Pollinators Not a Solution

The research may suggest that as honeybees continue to decline, turning to other species for pollinating crops in the U.S. is not the best alternative.

(Related:"Bees Like It Hot: Pollinators Prefer Warm Flowers, Study Reveals.")

Bee pollination accounts for $15 billion in added crop value, particularly for specialty crops such as almonds and other nuts, berries, fruits, and vegetables, according to the U.S. Department of Agriculture.

"People thought, The honeybees are disappearing, let's just use a different species"for pollinating plants, Cox-Foster said.

But the new research shows that the viruses can spread to other pollinators—"and they're likely exposed to the same stressors."

The bee-virus study appeared in the December 22 issue of the journalPLoS ONE.

forNational Geographic News

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Rock-Chewing Sea Urchins Have Self-Sharpening Teeth

Sea urchins are perhaps best known for their armor of spines. But their mouths may be even more daunting—urchin teeth can literally chew through stone without getting dull. (Related:"Eyeless Urchins 'See' With Spines.")

Now scientists are solving the mystery of how urchins keep their teeth so keen, and the research could lead to self-sharpening tools.

Sea urchins bore through rock to carve out nooks, where they can protect themselves from waves and predators. To learn how urchin teeth stay sharp despite all that grinding, researchers analyzed the roughly 0.1-inch-long (3-millimeter-long) choppers of the California purple sea urchin.

(Related:"Sea Urchin Genome Reveals Striking Similarities to Humans.")

Using high-resolution x-ray imaging, the investigators found that the teeth are mosaics of two kinds of calcite crystals: fibers and curved plates. The crystal shapes are arranged crosswise to each other and are bound together with a superhard cement of calcite nanoparticles.

Between the crystals are layers of weaker organic material. By striking the teeth with microscopic, diamond-tipped probes, the scientists found that the teeth break along these organic layers.

The scientists think the organics are predetermined weak spots in the teeth that allow parts of the material to"tear"away, similar to perforations in a sheet of paper. This means the teeth, which grow continuously, can regularly shed damaged areas to keep a well-honed edge.

(Also see"Bendable Concrete Heals Itself—Just Add Water.")

"Such an exquisite structure has evolved over 200 million years, and it can perform far better than manmade, nonoptimized tools,"said study co-authorPupa Gilbert, a biophysicist at the University of Wisconsin-Madison.

"Inspired by these discoveries, we can think of super-robust and fracture-resistant nanocements, or layered nanotips to do nanogrinding that rarely need replacing."

Much remains uncertain, though, such as the exact composition of the organic layers or the separate functions of the crystalline plates and fibers.

"Natural biominerals are wonderful, and we have a lot to learn from them,"Gilbert said.

The new analysis of sea urchin teeth was published online December 22 in the journalAdvanced Functional Materials.

forNational Geographic News

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"Chilling" Child Sacrifices Found at Prehistoric Site

The skeletons of dozens of children killed as part of a ritual bloodletting sacrifice a thousand years ago have been discovered in northernPeru, a new study says.

The remains are the earliest evidence of ritualized blood sacrifice and mutilation of children that has so far been seen in the South American Andes, according to study leaderHaagen Klaus.

Seeds of a paralytic and hallucinogenic plant calledNectandra, which also prevents blood clotting, were found with the skeletons, suggesting the children were drugged before their throats were slit and their chests cut open.

During the sacrifices, sharp bronze knives were used to hack the children to death. One skeleton had more than 25 cut marks on it. A few had their hands and legs bound with rope.

"It is so beyond what is necessary to kill a person. It really gives you the chills,"Klaus, an anthropologist at Utah Valley University in Orem, Utah, told National Geographic News.

"But we are trying to understand this on their terms, not ours."

(See relatedpictures:"Human-Sacrifice Chamber Discovered in Peru.")

Sacrifice Children Not Considered Human?

Eighty-two skeletons of the Muchik people—including 32 that were mostly or completely intact—have been discovered since 2003 at the Cerro Cerillos site in the Lambayeque Valley on Peru's arid northern coast.

(Related:"Ancient Tomb Found in Mexico Reveals Mass Child Sacrifice.")

It's unclear why their chests were cut open, but it may have been to cut out their hearts, Klaus said.

"They are offering the blood of these people ... they are feeding their ancestors and they are feeding the mountains,"said Klaus, whose study appears in December in the journalAntiquity.

In many Andean cultures, Klaus added, children may have been seen as conduits to communicate with the supernatural. What's more, in the Muchik cosmology, children may not have been seen as humans at all.

"When the Muchik began to sacrifice children, it's possible they were not sacrificing people in their eyes, as strange as it sounds,"he said in an email.

Maggots Part of Reverent Burial

After the bloodletting was over, the children were allowed to mummify in the desert air for at least a month, the study concluded. Empty fly pupa were found with the kids' remains, indicating that maggots ate their flesh during natural decomposition.

In ancient beliefs, the hatched fly carried deceased children's souls away and signified a reverent burial, according to Klaus.

Llama remains were also found with the bodies, suggesting that the funerals of many victims were accompanied by"solemn and very serious"feasts that included llama meat, Klaus noted.

The heads and legs of llamas were"given"to the dead, presumably to feed them in the afterlife.

(See"Inca Sacrifice Victims 'Fattened Up' Before Death.")

Sacrificial Evolution: From War Captives to Children

More than 80 sacrifices from A.D. 900 to 1100 were carried out by the Muchik people, who occupied the northern coast after the fall of the Moche.

The Moche were independently governed agricultural societies that ruled the region from about A.D. 100 to 800. (Read more about the Moche:"Odd Pyramid Had Rooftop Homes, Ritual Sacrifices?")

The Moche culture's political and religious ideology had started to disintegrate around A.D. 550, in the wake of a devastating El Niño, a cyclical phenomenon that can dramatically alter climate.

But some parts of the Moche culture persisted in the Muchik—including human sacrifice. The ritualistic killing of war captives had played a major role among the Moche elite as a way to appease ancestors and natural spirits, experts say.

The Muchik apparently developed a variation on the Moche sacrificial theme by sacrificing children, according to Klaus.

Muchik Left to Own Devices

The Muchik were able to develop their own rituals despite their rule by the ethnically distinct Sicán people, which began in A.D. 900.

While the Sicán also conducted human sacrifice, the methods of killing and settings contrast with those of the Muchik, Klaus said.

The Sicán, who likely had ties to what's now southern Ecuador,"came in during the power vacuum following the final Moche disintegration, and within a hundred years they created a powerful economy that rivaled that of the Incas 400 years later,"Klaus said.

The Sicán leaders focused largely on trade and were more skilled in metallurgy, fishing, agriculture, and llama herding. This focus on economics left the Muchik to their own ritual devices, Klaus said.

The Sicán's hands-off colonalism"is a completely different way of running a state than from what we are used to in the western system,"Klaus said.

(See relatedpictures:"'Mythical' Temple Found in Peru.")

Edward Swensonis an archaeologist at the University of Toronto in Canada who studies the Moche.

He said Klaus's argument that the Muchik sacrifice is rooted in Moche ritual is fascinating. But he questioned the argument that the grisly acts were purely an evolution of Moche ideologies during Sicán rule.

"Archaeologists have a tendency to reduce ritual to ... political control or resistance,"he said in an email.

"Obviously, there is much more to religion than simply political ideology."

forNational Geographic News

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Green Design Spree Aims to Trim U.S. Government's Big Energy Bill

This story is part of aspecial seriesthat explores energy issues. For more, visitThe Great Energy Challenge.

Sure, you've heard about Big Government. But have you seen its energy bill?

With $25 billion in annual power and fuel costs, the U.S. government is the largest single energy consumer in the nation's economy, and among the largest in the world. Of course, the 500,000 buildings the government leases or owns include not only office space, but supercomputers, hospitals, and aviation safety radar facilities. And the 600,000 vehicles that Uncle Sam has to tank up include those conveying troops engaged in active combat.

For years, it has been clear that there's a big opportunity in the sheer size of this energy footprint. The U.S. Congress has been setting federal efficiency goals since 1978—in hope not only of cutting costs and foreign oil dependence, but also of leading the way for energy savings in the private sector.

The Obama administration now is seeking to ramp up that effort dramatically—with the help of an unprecedented $4.5 billion in stimulus funds to be spent by next September entirely for federal green building and renovation projects. By executive order, the federal government is aiming to reduce its greenhouse gas emissions by 28 percent by 2020.

(Related:Pictures: Seven Supergreen U.S. Government Buildings)

"We have an opportunity to be an example for American building, a proving ground for what works,"says Bob Peck, commissioner of public buildings for the U.S. General Services Administration (GSA), the agency that manages real estate and procurement for the civilian government.

"We can show what kind of payback in energy saving do you really get, and just how efficient and effective these new technologies are--from {solar} photovoltaics, to smart advanced meters, to solar heating,"he says."And we're happy about this imperative, because it takes the government from being a follower to one of the first adopters."

Unheralded Success

In fact, the U.S. government has successfully reined in its power use since Congress first began setting targets in the wake of the 1970s energy crises. Energy use per square foot in U.S. government buildings has fallen nearly 30 percent since 1985. In ordinary commercial buildings in the United States, the trend has been headed in the opposite direction—with so-called"energy intensity"increasing 13 percent between 1992 and 2003, according tothe most recent figuresavailable.

"I've always found these figures striking,"says Jeff Harris, vice president for programs at the nonprofitAlliance to Save Energy, a coalition of business, government, and environmental groups focused on efficiency."I think we often haven't given enough credit to the work that has been accomplished."

But the challenges remain substantial. Even with the U.S. government's large efficiency improvement, its defense, safety, and science missions require so much juice that energy per square foot still is 30 percent higher than that of the private sector. And efficiency progress appeared to be slowing. Energy improvements had to be made out of the $1 billion per year the GSA typically is budgeted for new construction or renovation of its portfolio of federally-owned buildings. Last year,a reportby the U.S. Department of Energy's Federal Energy Management Program said that overall government energy intensity improvement was only 1.2 percent in 2008, less than half the goal of 3 percent per year set both by Congress and under an executive order by former President George W. Bush."The Federal Government is not likely to meet its goals in the coming years using a business-as-usual approach,"the report said.

The federal building projects that have been contracted with a total $5.5 billion in funds under the American Recovery and Reinvestment Act are meant to be a departure from business as usual. Congress stipulated that $4.5 billion of that total be spent on"green"building projects. So far, GSA has awarded 70 solar photovoltaic projects, projects for advanced electricity metering in more than 250 buildings, more than 200 lighting projects, more than 190 roofing upgrades, and 250 water conservation projects.

Opening Windows

And there are major renovations, such as the $160-million makeover of GSA's own headquarters, which will begin in January just a couple of blocks from the White House in downtown Washington, D.C. Here, the government hopes to reclaim some of the original features of the E-shaped building. Its large internal courtyards were designed to provide natural lighting and ventilation for those working inside when the structure was built in 1917.

"The buildings that were built before the age of air conditioners were designed as green buildings—they just didn't call it that,"says Peck."They had large windows and no one could have an office that didn't have access to daylighting. And the windows could be open on both sides of narrow corridors so the air could flow through."

But as has been typical in buildings in recent decades, the windows of the GSA building were painted shut many years ago so workers could not allow air-conditioned or heated air to escape. Peck says that one of the many innovations in the refurbished building–including solar water heating, a"cool roof,"and an extensive water recycling system—is simply a plan to allow workers to open the windows. The building still will have air-conditioning, but it will be controlled in separate zones. And Peck imagines that workers will sometimes receive email informing them when days are so hot they need to keep windows closed."We're going to have a hybrid system and we're going to learn some things about how you manage air temperature,"he says.

The U.S. government already has had success with new natural ventilation buildings, including the GSA office building in San Francisco, California, and new space for the U.S. Department of Energy's National Renewable Energy Laboratory in Golden, Colorado. In fact, since 2000, the U.S. government has had 310 buildings certified as high-performing examples of sustainable architecture under theU.S. Green Building Council's Leadership in Energy and Environmental Design(LEED) program, and 3,500 more federal buildings are pursuing certification."They are out in front on green buildings,"says Melissa Gallagher-Rogers, director of the government sector programs for the building council.

In late October, GSA said it would require that every new federal building and substantial renovation project meet the LEED"Gold"standard, an upgrade from the"Silver"target that had been in place since 2003."I think that there's a huge momentum that's being built up and I think we're just going to continue moving forward and improving the performance,"says Gallagher-Rogers.

Fueling Change

Nancy Sutley, who as chair of the White House Council on Environmental Quality is President Obama's chief environmental adviser, says the variety of the federal government's building portfolio may be as big a challenge as its size."We have every possible kind of building from the White House to a homeland security port of entry in Maine that's dealing with temperature extremes,"she says."So we're thinking about how to apply green building standards to a very diverse set of buildings."

And in working toward its greenhouse gas emissions goal for 2020, the federal government also will have to tackle the challenge of vehicle fuel. In fact, more than 60 percent of the government's energy consumption is for transport—particularly jet fuel.

(Related:"First Green Supersonic Jet Launches on Earth Day")

But Sutley says that the Department of Defense, with numerous programs to shift to greener fuels and reduce oil dependence, has set one of the most aggressive greenhouse gas reduction targets government-wide: 34 percent by 2020.

"Fuel is a huge cost for them dollar-wise, but it also is a huge cost when they have to send these fuel convoys hundreds of miles into Afghanistan to provide fuel to the troops, putting people's lives at risk,"Sutley says."So reducing their operational energy is also protecting the troops, and it also is an example of how across the federal government, agencies are recognizing that sustainability is mission-critical."

(Related: National Geographic'sPersonal Energy Meter)

Yewon Kang and Zak Koeske of Medill News Service in Washington, D.C. contributed to this report.

ForNational Geographic News

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